Burners are well known devices. For example, U.S. Pat. No. 4,708,637 discloses a gaseous fuel reactor which is composed of a plurality of concentric casings which form a primary air chamber, a secondary air chamber, and a tertiary air chamber. This patent states the flow of gas and air through the various chambers interact to provide controlled flame characteristics. Also, the flame is maintained at a lower temperature to avoid the formation of pollutants.
Improvements to burners remain desirable, including burners with reduced emissions and lower fuel consumption for a given amount of heating.